wr250x popping on decel after mods bad?

hey guys i recently installed did some mods to my 09 wr250x and it pops a little on deceleration, I am just wondering if its something that I should be worried about...

I recently installed a fmf powercore4, fmf efi programmer(and tuned it accordingly), graves smog block off kit, and removed the ais system and taped open the air box flapper. the bike sounds great, hauls ass and rides exactly how i want it to, but im just curious to know if i am killing my bike? everything else seems to sound normal, its just the popping/ cackle when i am ripping it and then let off the throttle quickly.

be kind

yngdviant wrote:

fmf efi programmer(and tuned it accordingly)

How exactly did you "tune it accordingly"?

What numbers are you running?


And which is it?

Is it backfiring "bad" as your title says?

Or is it just a "little pop" as it states in the body of your post?






From what I've been told, and what I've experienced, some backfiring can indicate running a little lean, and bumping up a few of the settings on the efi programmer could fix everything.

Without know what numbers you're currently running it's hard to know what to suggest for you at this point.

When you removed the AIS did you do something with this hole?



Like perhaps buy something to close it off, or fashion some kind of plate to close it off?

Like this: (sorry for fuzzy pic...)




Did you follow all the steps outlined in both sections here. <-- clicky

motokid wrote:

When you removed the AIS did you do something with this hole?



Like perhaps buy something to close it off, or fashion some kind of plate to close it off?

Like this: (sorry for fuzzy pic...)




Did you follow all the steps outlined in both sections here. <-- clicky

I don't think I said it was back firing just a little popping on the roll off. I bought the tuner used from a guy on here and he recommended 3-g 4-y 1-r 8-gb 4.5-yb 4-rb and I'm pretty sure he had a real similar set up. and yes I removed the ais with the help of a YouTube video with a Korean guy and installed the smog block off kit to cover the holes in your picture as well as the airbox hole where you disconnect the tube that runs to the hole that I covered. btw I'm the same guy who posted in the other thread you replied to so I'm just gonna reply to this one now

it kinda sounds like a tuned v8 mustang

But is it "bad" popping as title states - or just a little popping as post states?


I read "popping" to be back firing.

I think you need to explain better what you mean by "popping". the way I use it, popping is just the sound coming from the exhaust and this happens even with a 100% stock bike if you downshift hard + let the clutch slip a bit. If I intentionally do it I can make it "pop", but it will (not very frequently) just do it on it's own. it's not very loud, just several pops in quick succession.

a backfire is quite different in which case the unburnt gasses reignite when they come in contact with oxygen, and you'll hear this as a pretty loud BANG. quite a big difference there.

so "popping" the way I use it, won't do any harm, a backfire, if it happens regularly on the other side probably will do some damage sooner or later.

I dont think its a back fire. its like consecutive pops pretty close to one another after i go hard on the throttle and then let off with it still in gear. they arent as loud as a backfire. there may be a leak in the exhaust. I noticed one of the four screws on the slip on did not fully screw in tightly when i repacked it on the powercore 4. It stays in snuggly but it keeps screwing (if that makes sense.) Im gonna try to seal it up with some hondabond when i get the chance. I haven't even been riding the bike for fear of causing damage.

i think the bike is running rich. I also just redid the oil and oil filter with top quality oil (cost me 40 fuckin dollars for 2 liters and the filter) put in the exact amount according to the manual, 1.4 liters, and after riding it i noticed that the oil seems like it is a little more liquidity then oil should be. it was also right between the lines like it should be right after i changed the oil (yes it was balanced and not leaning on the stand), and now it fully fills up the window. not 100% positive that gas has seeped down into the crankcase, as i smelled it and it was hard to determine if it smelled like gas or oil.

It just gives me suspicion that the bike is running rich... idk anybody else have these symptoms? i feel like its a matter of changing the numbers on the programmer but idk what to. I may buy the k & n air filter because the one currently in it is kind of dirty so that may lean it up a bit.. im about to take it to a dyno shop and have them tweak it to avoid doing some serious damage for continuing to ride the way it is, but they want like $350. It would be nice if i could troubleshoot this myself so i could use that on tires instead.

the bike doesnt seem to bog or anything. it sounds and rides great, its just the popping on the decel after a hard acceleration. very responsive and gives me full pulling power to the rev limiter from any rpm. the idle may be off beat every once in a while when it is cold and first started up but once its warm the idle is consisted

1) a little "popping" once in a while isn't hurting anything

2) why was your oil change so expensive? did you pay somebody to do it for you?

3) use the sight glass when replacing oil - don't go by the manual's stated volume. You run the risk of over-filling that way.

4) if you think bike is running rich - and you have an efi programmer - why won't you just change the damn settings on it?

5) are you an extremely paranoid person about everything?


Sounds to me like you need to relax.

Where do you live? Maybe somebody here lives close enough to you to meet up somewhere and help you get over your anxiety about your bike?

These things are damn near bullet proof. You'd really have to try to damage it.


1) please list any and all modifications your bike has that have changed it from stock
2) what numbers are you running on your efi programmer?
3) what's you're overall experience with riding a motorcycle?

motokid wrote:

1) a little "popping" once in a while isn't hurting anything
im just worried if its running rich because that could cause damage.

2) why was your oil change so expensive? did you pay somebody to do it for you?
I did the oil change myself, it cost so much because i was trying to be good to my bike and put in Repsol 10W40 Moto Racing 4T Synthetic Oil which was like 18 a bottle at a motorcycle shop.

3) use the sight glass when replacing oil - don't go by the manual's stated volume. You run the risk of over-filling that way.
I did use the volume the manual stated but it was on par the line levels after i ran it and checked it before taking it on a longer ride couple rides and then checking again.

4) if you think bike is running rich - and you have an efi programmer - why won't you just change the damn settings on it?
and i haven't really had time to yet, but i dont have much experience with the programmer. i know how to use it but only to plug in the numbers recommend. this is the first bike ive had that was a liquid cooled fuel injected 4 stroke. been riding n/a trail 4t and mostly 2t my whole life.

5) are you an extremely paranoid person about everything?
no i just dont want to blow up my $6590+mods bike

Sounds to me like you need to relax.

Where do you live? Maybe somebody here lives close enough to you to meet up somewhere and help you get over your anxiety about your bike?
i live in northern va, never seen anybody with one around except for i think i passed a guy with a stock wr250r the other day.

These things are damn near bullet proof. You'd really have to try to damage it.


1) please list any and all modifications your bike has that have changed it from stock
i listed these already- they are fmf powercore4, fmf efi programmer(and tuned it accordingly), graves smog block off kit, and removed the ais system and taped open the air box flapper.
2) what numbers are you running on your efi programmer?
listed these too- running 3-g 4-y 1-r 8-gb 4.5-yb 4-rb
3) what's you're overall experience with riding a motorcycle?

ive been riding dirt for over 10 years now, this however is my first street bike and racing 4 stroke type of motor. I have trail bikes like an xr200 and crf150 but those a not even close to the same. mostly dealt with 2 strokes like a cr125 and yz250

ive also never had a bike that has an oil window, so the possible sight of having gas in the crankcase worries me. if any of my bikes did this in the past, it was much harder to tell

I would not say our motors are "racing 4 stroke" type motors.

They're built to be bullet proof.

How old is your bike? How many miles?

yeah many not like a yzf but isn't it like a fourth of an r1 pretty much. I've just always had a naturally aspirated trail bike with a carb when I've own four strokes so I am much more familiar with those.

the bike is an 09 with about 1500 miles although I am not sure if that is the exact number as it was a salvage an I think the odometer may have been replaced. certainly don't think it's close to 26000 though when you need to adjust the valves

yngdviant wrote:

yeah many not like a yzf but isn't it like a fourth of an r1 pretty much. I've just always had a naturally aspirated trail bike with a carb when I've own four strokes so I am much more familiar with those.

the bike is an 09 with about 1500 miles although I am not sure if that is the exact number as it was a salvage an I think the odometer may have been replaced. certainly don't think it's close to 26000 though when you need to adjust the valves

SALVAGE?????????

That's cause for concern.

Do you know why it's a salvage?


Yes - common thought is that it's a somewhat detuned 1/4 of an R1 motor.

yes it was stolen in 2010 shortly after the first owner purchased and written off for insurance. it's never been wrecked and was pretty much in new condition when I bought it. I know a few of the lights were parted and replaced. not sure about the odometer though

I'm confused as to why any bike, stolen or not, would be stamped with a "salvage" title unless it was wrecked.

But I sure don't know how insurance companies work either.

So yeah - a little popping after hard, wide-open throttle acceleration and then basically closing the throttle completely isn't abnormal, and I'd say it's probably pretty normal.

Nothing I'd be concerned with. In fact I'm not concerned because my bike does that too.

You put a high dollar synthetic oil into your bike very recently right? Any clue what oil was in it before? Possibly not synthetic?
You'll never drain all the old oil out. So when you refill you'll have some small amount of old oil mixing with the new stuff.

What's your oil look like in the sight glass? Why do you think gas might be mixed in?

Since the same oil in our bikes that lubes engine parts also cycles through the clutch, don't be confused or concerned about it getting a little darker in color rather quickly after you put the new stuff in.

yngdviant wrote:

running 3-g 4-y 1-r 8-gb 4.5-yb 4-rb

If you think you're a little rich try these numbers: 2-2-.0.5-8-5-4

A guy named r6realtor posted these and he says his bike "rips" now.

motokid wrote:

I'm confused as to why any bike, stolen or not, would be stamped with a "salvage" title unless it was wrecked.

But I sure don't know how insurance companies work either.

salvage titles are given when the bike is consider like >=75% damaged (or some number close to that) since it was stolen i guess it was considered %100 according to that law. it then had a lien put on it and then was eligible to be retitled which is when i bought it.

id say the bike does sound pretty normal its just the popping which i have read is a sign of running rich. I am going to replaced the air filter with a k&n because its due for one and hopefully that will give it a little more air.

as for the oil i was concerned that the consistency was a little to watery to be like oil but i dont even know. i read that gas leaking in the crankcase is another sign of running rich. i tried to smell it but its kind of hard to determine whether it smells like gas or oil or a mixture.. It is definitely way over the max line though when it is balanced. when i checked it right after i changed the oil and filter, and ran it for a minute, it was perfectly in between the lines. I am going to have to drain some when i find some time. i work 7-7 in the week so i havent even really been able to look at it.

Im also gonna check the plug color when i get some time to do all this.

thanks for the numbers, i will experiment with it when i do all the other stuff hah

Gas "leaking into crankcase" is not a sign of running rich - it's a sign of bigger problems.


If you're running rich you'll have a really strong smell of gas coming from exhaust pipe, backfiring issues, the end of your exhaust pipe might have a wet sooty gunk form on it, and generally you'll have much poorer fuel mileage.

My 2012 is stock, with the exception of the stock spark arrestor/tip swapped for a graves hi flo.  I notice a lot more popping on decel especially w engine braking.  I wouldn't worry about it, unless the pops are so loud that they sound like backfire.

Popping on decel is a sign of leanness in the exhaust...not richness.  It can be caused by a too lean fuel mixture off idle or more often,  a leak in the exhaust itself.  Resist changing your FMF Programmer to fix the situation until you're sure you have no exhaust leaks or you'll be masking the cause.

I added a FMF Powercore 4 and was told I would need a fuel programmer of some sort because the bike would run lean. With just the slip on I don't remember any popping or backfire, just a delay in acceleration...but I could be wrong and it did...I do know that after installing the FMF Programmer with the settings provided I notice very slight popping infrequently during deceleration and probably 3 backfires( not super loud ) in 10 days. Bike rides great and accelerates great so I'm confused...Bike isn't cheap and don't want to F up the engine. I used High Temp silicone on the pipe install but maybe I didn't get It all the way around for a perfect seal?! Just looking for some one to tell me it's all going to be ok!?! Bought the pipe for a little extra noise and to not have an off the show room look, not to spend $900 on a pipe, powercommander 5 and a dyno. Any input is welcome.
Steve

sshabro wrote:

I added a FMF Powercore 4 and was told I would need a fuel programmer of some sort because the bike would run lean.  With just the slip on I don't remember any popping or backfire, just a delay in acceleration...but I could be wrong and it did...I do know that after installing the FMF Programmer with the settings provided I notice very slight popping infrequently during deceleration and probably 3 backfires( not super loud ) in 10 days.  Bike rides great and accelerates great so I'm confused...Bike isn't cheap and don't want to F up the engine.  I used High Temp silicone on the pipe install but maybe I didn't get It all the way around for a perfect seal?!  Just looking for some one to tell me it's all going to be ok!?!  Bought the pipe for a little extra noise and to not have an off the show room look, not to spend $900 on a pipe, powercommander 5 and a dyno.  Any input is welcome.
Steve

Have you removed the AIS junk?
What settings you running on programmer?

A little pop here and there isn't going to hurt anything.

I installed my FmF Q4 years ago and never used silicone or nothing to seal between header and slip-on.

Any and all popping I have ever had has been due to, and or controlled with programmer settings.